Workbenches are used to support and often secure work pieces in a desired orientation. Vises, hold-downs and other structures are often incorporated in or attached to workbenches to facilitate securing work pieces. Such woodworking benches utilized in the west often include two vises for holding work pieces, a “front vise” with vise jaw faces parallel to the front of the workbench and a “tail vise” with vise jaw faces perpendicular to the front of the workbench. Right handed woodworkers typically find the front vise most usefully located at the left end of the bench and the tail vise most usefully located at the right end.
Whether located at the right or left end of the bench, the tail vise is generally used for clamping long panels, boards or other work pieces against bench dogs or other stops, one or more of which is located in the top of the bench and the other of which is in the vise jaw. Alternatively, dogs or stops may be positioned on the front apron of the bench and the front of the vise jaw. Work pieces or jigs or other objects can also be captured between an end of the tail vise jaw and an end of the bench apron, which serves as the stationary one of the two vise jaws.
Also without regard to location at the right or left end of the bench, a front vise is generally used for clamping boards of various lengths, and shapes between a front vise jaw and a rear jaw or the front edge of the bench, which often serves as, or is part of, the front rear jaw of such vises. Like the tail vise, the movable jaw of a front vise can carry one or more bench dogs that are used with one or more bench dogs positioned in the top of the bench behind the front vise.
Rotation of vise screws move the movable vise jaw relatively slowly in order to provide significant mechanical advantage. As a result, many vises and vise mechanisms have “quick release” functionality to permit the movable jaw to be slid quickly open or closed to a position in contact with work piece. Known such mechanisms permit the vise jaws to apply significant closing pressure. However, vises that permit the jaws to be opened or separated with the screw mechanism applying significant force are useful in certain clamping and component separation processes.
Typically, the screw mechanisms for tail vises are built into the jaw, requiring substantial woodworking skill and effort to install and align. Often, the overall design of a bench must be modified to accommodate these mechanisms, and retro-fitting a tail vise mechanism to an existing bench can be very difficult.
Front vises generally have a movable jaw parallel to the front edge of the bench that moves perpendicular to that front edge. In some such vises the front jaw is sometimes supported by rods that pass from the bench into the lower portion of the front jaw. In other such vises, sometimes called “leg” vises. the front jaw component extends from the top of the bench almost to the floor parallel to one of the bench front legs. A large screw, often made of wood, typically passes through the front jaw and is threaded into the adjacent bench leg or another threaded, stationary member. Rotation of the screw in one direction releases the jaw and rotation in the other direction tightens it. Such “leg vise” front jaws are supported by the screw and, typically, a generally horizontal member that extends from the lower end of the jaw into an opening in the leg. A transverse pin through an appropriate one of a series of holes in the horizontal member counter-balances the force exerted by closing the screw in order to apply force with the upper end of the vise jaw that is pressed in the direction of the front of the bench.
Yet another type of front or “shoulder” vise on woodworking benches is sometimes referred to as a “Scandinavian-style” vise. It utilizes a screw that moves through a threaded member that is part of or attached to an arm that is mounted to project from a support attached to the front of the bench so that the arm projects parallel to but spaced several inches away from the front of the bench. The screw acts on a paddle-like front jaw, forcing it in the direction of the front of the bench in order to capture a workpiece between the paddle-like jaw and the front of the bench.
Many vises use a clamping screw passing through the jaws and exposed within the clamping space between the jaws. This screw is often coated with lubricant to facilitate smooth operation of the vise and protect the moving parts from corrosion. Where a clamped workpiece contacts this screw, it can be contaminated by the lubricant and otherwise damaged. This is particularly troublesome in woodworking, because the lubricant can be absorbed into the workpiece, and interfere with subsequent applications of adhesives or finishes. Further, contact with the screw thread can damage the workpiece by denting the surface, which at best requires work to remove the damaged section, and at worst can render the part useless if the damaged surface has already been brought to finished dimensions.